For those who say they do not have enough space to store or transport modules here are some ideas.

This is my latest, at 22" long the Western Union's shortest. It weighs less than 1.5Kg, probably just over when finished.
These short "mini modules" came from the short end modules that RS Tower have. We at Western Union have made several through versions, they don't have legs, but are clamped between other modules. There is a limit to the number that can be used in a layout, as they can only fit between full modules, but do add useful length to space out modules.

This one was made to fill a gap on our junction module's stored configuration. This is about 4 hours work so far.
It could be paired with a ply or even card cover or another module. This would fit any car or even could be carried on a bus or train.

Causeway is a corner that folds in two, about 36" long, this is a full module and requires legs. The legs are fitted into sockets and I'm sure could be made foldable or extendable to make them easier to carry.

As can be seen, I don't go for flat scenery and even the new one has the foam base cut away to make a river and flood plain. It had to cut out to clear a tower on the opposing board, I extended this to make the river.

The small one is smaller than a medium suitcase and can be lifted with a little finger. In fact on checking, if 1cm narrower, it would be allowed on British Airways as hand luggage! In fact two boards face to face would still fit. The x-ray could prove interesting!
With a shoulder bag or rucksack for some clamps, cables and a bit of stock it could well be taken almost anywhere. We do have some members that travel to meetings by bus, so this is a possibility for them.

Even the corner module is only around the size of a larger suitcase, but would need legs. On the other hand I'm pretty sure it would fit in the passenger seat of a Smart car or boot of a taxi.

I doubt a bus is worse than my trailer over potholes. I can tell that the boards jump over an inch in the trailer from where they end up. They also get dropped off kerbs, etc. when moving in and out of venues.
Mobile layouts have to be built strong or else you have lots of trouble. The boards have to line up reliably every time. Scenery and buildings have to be well fixed down as they often hang on edge or upside down while being moved.
My current module has withstood over 14 years of this monthly abuse, with no more than a few scratches.

The railroad has been dumping rubble to stop the creek eroding the lefthand bank, well that's my excuse for the shape of the creek (it has to clear a structure on the opposite board it is mated to for transport), but I wanted full height foam for a few inches from the end on the sides.

A view of the underside, very simple wiring on this one! The panels and trunking are glued on with no-nails type adhesive. The x-bus sockets are not fitted as I just jump the module with a longer lead.